# ri completion for Ruby documentation                     -*- shell-script -*-
# by Ian Macdonald <ian@caliban.org>

_ri_get_methods()
{
    local regex

    if [[ $ri_version == integrated ]]; then
        if [[ -z $separator ]]; then
            regex="(Instance|Class)"
        elif [[ $separator == "#" ]]; then
            regex=Instance
        else
            regex=Class
        fi

        COMPREPLY+=(
            "$(ri ${classes[@]+"${classes[@]}"} 2>/dev/null | ruby -ane \
                'if /^'"$regex"' methods:/.../^------------------|^$/ and \
            /^ / then print $_.split(/, |,$/).grep(/^[^\[]*$/).join("\n"); \
            end' 2>/dev/null | sort -u)")
    else
        # older versions of ri didn't distinguish between class/module and
        # instance methods
        COMPREPLY+=(
            "$(ruby -W0 $ri_path ${classes[@]+"${classes[@]}"} 2>/dev/null | ruby -ane \
                'if /^-/.../^-/ and ! /^-/ and ! /^ +(class|module): / then \
            print $_.split(/, |,$| +/).grep(/^[^\[]*$/).join("\n"); \
            end' | sort -u)")
    fi
    ((${#COMPREPLY[@]})) &&
        COMPREPLY=($(compgen $prefix -W '"${COMPREPLY[@]}"' -- $method))
}

# needs at least Ruby 1.8.0 in order to use -W0
_ri()
{
    local cur prev words cword split
    _init_completion -s -n : || return

    case $prev in
        --help | --width | -!(-*)[hw])
            return
            ;;
        --format | -!(-*)f)
            COMPREPLY=($(compgen -W 'ansi bs html rdoc' -- "$cur"))
            return
            ;;
        --doc-dir | -!(-*)d)
            _filedir -d
            return
            ;;
        --dump)
            _filedir ri
            return
            ;;
    esac

    $split && return

    if [[ $cur == -* ]]; then
        COMPREPLY=($(compgen -W '$(_parse_help "$1")' -- "$cur"))
        [[ ${COMPREPLY-} == *= ]] && compopt -o nospace
        return
    fi

    local class method prefix ri_path ri_version ri_major separator IFS
    local -a classes

    ri_path=$(type -p ri)
    # which version of ri are we using?
    # -W0 is required here to stop warnings from older versions of ri
    # from being captured when used with Ruby 1.8.1 and later
    ri_version="$(ruby -W0 $ri_path -v 2>&1)" || ri_version=integrated
    [[ $ri_version != "${ri_version%200*}" ]] && ri_version=integrated
    [[ $ri_version =~ ri[[:space:]]v?([0-9]+) ]] && ri_major=${BASH_REMATCH[1]}

    # need to also split on commas
    IFS=$', \n\t'
    if [[ $cur == [A-Z]*[#.]* ]]; then
        [[ $cur == *#* ]] && separator=# || separator=.
        # we're completing on class and method
        class=${cur%$separator*}
        method=${cur#*$separator}
        classes=($class)
        prefix="-P $class$separator"
        _ri_get_methods
        return
    fi

    if [[ $ri_version == integrated ]]; then
        # integrated ri from Ruby 1.9
        classes=($(ri -c 2>/dev/null | ruby -ne 'if /^\s*$/..$stdin.eof then \
        if /^ +[A-Z]/ then print; end; end' 2>/dev/null))
    elif [[ $ri_major && $ri_major -ge 3 ]]; then
        classes=($(ri -l 2>/dev/null))
    elif [[ $ri_version == "ri 1.8a" ]]; then
        classes=($(ruby -W0 $ri_path |
            ruby -ne 'if /^'"'"'ri'"'"' has/..$stdin.eof then \
            if /^ .*[A-Z]/ then print; end; end'))
    else
        classes=($(ruby -W0 $ri_path |
            ruby -ne 'if /^I have/..$stdin.eof then \
                if /^ .*[A-Z]/ then print; end; end'))
    fi

    ((${#classes[@]})) &&
        COMPREPLY=($(compgen -W '"${classes[@]}"' -- "$cur"))
    __ltrim_colon_completions "$cur"

    if [[ $cur == [A-Z]* ]]; then
        # we're completing on class or module alone
        return
    fi

    # we're completing on methods
    method=$cur
    _ri_get_methods
} &&
    complete -F _ri ri

# ex: filetype=sh
